Sleep loss is a common consequence of modern society's increased demands on time. Epidemiologic studies have shown that both shorted sleep durations are associated with increased cardiovascular disease (CVD) and mortality. Severe sleep loss has been shown to have significant effects on immune and neuroendocrine factors, including elevating levels of high-sensitivity C-reactive protein (hs-CRP), an inflammatory marker of CVD risk. The proposed study will be the first to investigate the effects on CVD inflammatory markers from partial sleep deprivation and inadequate recovery sleep at levels more commonly experienced in the stress of daily life. Recent research also indicates that early life stress (low childhood socioeconomic status and harsh family environment) are associated with adult levels of hs-CRP, through pathways of psychosocial dysfunction and high body mass index, as well as with autonomic reactivity. As such, early life stress may potentiate inflammatory responses to sleep loss. Therefore, this research will examine in healthy adults the extent to which early childhood environment and related psychological factors, and inadequate recovery from sleep deprivation promote changes in hs-CRP and other inflammatory markers of CVD (resistin, adiponectin and leptin). To accomplish these goals, N=180 healthy adult volunteers will undergo an 11.5-day protocol under controlled laboratory conditions. They will have 2 nights of baseline sleep (10 hours in bed), followed by 5 nights of sleep restricted to 4 hours per night, followed by varying dosages of recovery sleep on 2 consecutive nights, and then 2 full nights of recovery sleep. The sleep dosages to which subjects will be randomized on each of the first 2 recovery nights will be 0, 2, 4, 6, 8, or 10 hours. Blood samples will be collected and assayed for inflammatory markers at baseline, after partial sleep deprivation, and following recovery sleep nights 1 and 2. The following research questions will be addressed: 1. Does inadequate recovery sleep following partial sleep deprivation elevate hs-CRP? 2. Does a history of childhood stress potentiate the inflammatory response to sleep loss? 3. Are other markers of cardiovascular risk (resistin, adiponectin, leptin) affected by inadequate recovery from partial sleep deprivation? If inadequate recovery from partial sleep loss at levels commonly experienced by people are found to increase circulating inflammatory markers of CVD risk-alone or in combination with psychosocial factors-this project will have an important public health outcome. Sleep deprivation is a behavioral factor that can be modified without prohibitive expense, making it possible to decrease risk for a common cause of mortality in the U.S. through public awareness and education. [unreadable] [unreadable] [unreadable] [unreadable]